The present invention broadly relates to a fender for ships and, more particularly, to an improvement in a hollow rubber fender of the type having a hollow frusto-conical elastic body made of rubber adapted to be fixed to a quay wall such that the axis of the body extends perpendicularly to the plane of the quay wall.
The present inventor has proposed, in Japanese Utility Model Publication NO. 55299/1981, a rubber fender which is improved to increase the energy absorption power of conventional bowl-shaped fenders. More specifically, this fender comprises a frusto-conical hollow main body and a thick-walled disc-shaped buffer portion projecting from the smaller-diameter end of the main body coaxially with the latter. The thick-walled buffer portion projects from the smaller-diameter end of the hollow frusto-conical main body by a considerable height, e.g. by an axial length of 0.15 H for axial length H of the main body. In operation, this buffer portion is made to contact with the ship's side earlier than the other portions of the fender to effectively absorb a part of the inertia of the large mass of the ship to be moored. Thus a considerably long time is required until the main body is inflated to bring its outer surface into contact with the ship's side. As a consequence, the deformable part of the main body is increased to offer a remarkable increase in the energy absorption power thereof.
Although the rubber fender of the prior art exhibits a high energy absorbing performance, it is so stiff that the fender exerts a considerably high reaction force to the ship's wall when it is in contact therewith. Thus, there is a risk that the ship's wall may be damaged by the rubber fender.